Pozzolans can be used in combination with Portland Cement to produce products of superior strength and chemical resistance. The slow rate of strength gain has limited the practical amount of Portland Cement replacement with pozzolan.
Pozzolan accelerators based on alkali metals have been used to increase the practical amount of Portland Cement replacement with pozzolan. These alkali accelerators maintain a high pH and provide soluble alkali metals required for pozzolonic acceleration. Common accelerators include alkali silicates, carbonates and hydroxides. An unfortunate feature common to alkali-metal based pozzolan accelerators, and other currently available accelerators, is their caustic nature. Caustic accelerators can cause contact burns and present significant safety risks.
Pozzolan accelerators are needed that maintain high levels of Portland Cement replacement while providing a safe, stable alternative to caustic accelerators.